Interpretive Summary: In response to the public's concern for pesticide usage, the pest control industry is seeking new and less toxic approaches to pest control. Our studies with 3 species of urban pest ants demonstrate that a 1% concentration of boric acid mixed with 10% sugar in water is effective at eliminating entire colonies. Boric acid baits currently available use a higher concentration of boric acid, so the results of this study indicate that the active ingredient can be reduced considerably. In addition, the carrier and attractant in this bait are ideal. Water is a good carrier for ants which feed primarily on liquids and the sugar attracts species of ants which collect honeydew.

Technical Abstract:
A 1% boric acid - sucrose water bait and 0.9% hydramethyinon granular bait were evaluated for efficacy against small laboratory colonies of Tapinoma melanocephalum (Fabricius), Linepithema humile (Mayr) and Monomorium pharaonis (L.). In T. melanocephalum colonies exposed to boric acid bait for 3 d or continuously, workers were reduced by 97% in the first week and brood reduced by 96% in the third week. The hydramethyinon bait did not significantly effect colony growth. For Linepithema humile colonies exposed to boric acid bait for 3 d, workers and brood were reduced 75% and 88% respectively by the third week; colonies exposed continuously showed 90% reduction of workers and brood by the third week. Reduction of worker and brood in colonies which were exposed to hydramethyinon bait were 86% and 77% respectively after 3 wks. In Monomorium pharaonis colonies exposed to boric acid bait for 3d, workers and brood were reduced 60% and 50% respectively by the eighth week; colonies exposed continuously to boric acid or hydramethyinon bait showed over 90% reduction of workers and 60% reduction of brood by the third week